Percentage Calculator

The percentage calculator solves "X percent of Y is Z" problems, computes percent change between two values, and converts a percentage into its decimal, fraction, and ratio equivalents. Any two of X, Y, and Z are enough to solve for the third.

• X is the percentage, Y is the base value, and Z is the result; leaving one of the three blank solves for it from the other two.
• X can also be read as a decimal, a fraction, or a ratio alongside the percentage.
• A separate percentage difference calculation measures the increase or decrease between an original value and a new one.

• Find Z: Z = (X ÷ 100) × Y
• Find X: X = (Z ÷ Y) × 100
• Find Y: Y = Z ÷ (X ÷ 100)
• Percent Change: ((New − Original) ÷ Original) × 100

Solving for Z when X is 15 and Y is 80: Z = (15 ÷ 100) × 80 = 12. A percent change from 80 to 92 is ((92 − 80) ÷ 80) × 100 = 15%, an increase.

• Percentages can be entered as plain numbers or with the % symbol, fractions as a/b, and decimals as standard numbers.
• Y and Z take whole numbers or decimals; only one field in the X-Y-Z group should be left blank at a time.
• The result sentence below the inputs states the exact calculation performed, worth checking against the intended operation.

Percentage problems come up constantly in finance, education, statistics, and everyday decisions. The scenarios below cover the typical calculations.

• Calculate sale prices, discounts, and markdowns to plan purchases.
• Estimate tips, taxes, and surcharges to preview final totals.
• Measure investment growth, returns, and fee impacts using percent change.

• Solve homework problems about parts, wholes, and percentage relationships.
• Convert between percentages, decimals, fractions, and ratios to strengthen number sense.
• Check answers with precise outputs and formatted conversions.

• Compare category differences and trend changes with percent change.
• Communicate results with consistent formatting for decimals, fractions, and ratios.
• Standardize calculations for audits, dashboards, and summaries.

The statement describes part of a whole. X expresses the portion per hundred, Y is the whole or base, and Z is the resulting part. For example, 25% of 200 is 50.

The percent change formula, ((New − Original) ÷ Original) × 100, gives both magnitude and direction: a positive result is an increase, a negative result is a decrease.

Decimals suit quick arithmetic, fractions preserve exact values, and ratios suit direct comparison; all three express the same percentage in a different form.

The result sentence confirms which operation was performed, such as "X% of Y is Z." The same percentage appears as a decimal, a fraction, and a ratio for comparison, and the percent change output states both the direction and magnitude of the difference.